DMI 10 Homework #1

ARRT

American registry of radiologic technologist

Isotope

Atoms that have the same number of protons but a different number of neutrons

Why is ALARA important?

Because keeping radiation exposure as low as reasonably achievable will protect the patient as well as yourself from unnecessary radiation exposure.

Hypersthenic

Big frame, overweight

What is the difference between CAT scan and MRI?

CAT scan uses radiation and is for cross sectional and 360 degree imaging and MRI uses magnetic resonance and is mostly for soft tissue and organs.

List the modalities that use ionizing radiation to produce images

Computed Tomography, Radiography, Fluoroscopy, Nuclear medicine, Mammography, radiation therapy

Potter-Bucky grid

Device with aluminum fins used to reduce the intensity of scatter radiation in the remnant x-ray beam.

Insulators

Do not allow electricity to flow through them easily (wood, plastic, rubber, glass, oil)

Fractionated

Dose is delivered at the same dose rate at specific intervals

Image intensifier

Electronic vacuum tube that amplifies a fluoroscopic image to reduce patient dose. To increase intensity of light.

Low voltage

High current, tends to throw the victim

Protracted

If dose is delivered continuously but at a lower dose rate (ex. Prostate cancer patients- isotopes)

Fluoroscropy

Imaging modality that provides a continuous image of the motion of internal structures while the X-ray tube is energized. Real-time imaging.

Snook Transformer (1907)

Interupterless Transformer - glass tube

Current

Is the motion of electrons

KVp

Kilovolt peak - measure of the maximum electrical potential across an X-ray tube; expressed in kilovolts.

High voltage

Low current, tends to hold the victim

Explain when, who, and how x-rays were discovered?

November 8, 1895, Wilhelm Roentgen accidentally discovered x-rays while studying cathode rays through a Crookes tube. He found that an item he had laying around near the Crookes tube was giving off fluorescent lighting, which was actually a coating of barium platinocyanide. He continued to study the source of the "x-light" which ultimately resulted in his first medical x-ray image, which was an image of his wife's hand.

Give examples of radiation protective equipment

Protective apparel such as lead-impregnated material gloves, aprons, gonadal shielding, and leaded-glass windows.

Rem

Radiation equivalent man - special unit for dose equivalent and effective dose. It has been replaced by Sievert (Sv) in the SI system. 1 rem= 0.01 Sv.

RSO

Radiation safety officer - that individual-physician, medical physicist, or technologist- assigned to develop and implement the radiation safety program.

Ionized

Referring to an atom that has had an electron removed

Collimation

Restriction of the useful x-ray beam to reduce patient dose and improve image contrast.

Asthenic

Small, frail, often elderly (most technique)

Binding energy

Strength of attachment of an electron to the nucleus

Sthenic patient

Strong, active, average

Radiobiology

The study of the effects of ionizing radiation on biologic tissue

Hyposthenic

Thin but healthy

List the modalities that DO NOT use ionizing radiation to produce diagnostic images

Ultrasonography and magnetic resonance imaging

Coolidge X-ray tube (1913)

Vacuum tube - glass tube

mAs

mA x seconds (time) product of exposure time and X-ray tube current; measure of the total number of electrons

Conductors

materials that allow electric charges to flow through them easily (metals)